Ureteral stent, methods and uses thereof

Abstract

Stents and methods for producing stents are provided. The stent includes a polymeric substrate comprised of 10-50% (w/w) of alginate and 45-85% (w/w) of gelatine and further includes a polymeric biodegradable resin for coating said polymeric substrate. The stent can also include a contrast agent. The stent can further include a crosslinking agent. The method for producing the stent includes dissolving the alginate and gelatine in water and stirring to obtain a polymeric substrate. The method also includes adding a crosslinking agent to the substrate, injecting the substrate into a mold to obtain the stent, placing the stent in a first alcohol solution, and placing the stent in a crosslinking agent solution. The method further includes placing the stent in a second alcohol solution, and a series of interchanging drying and immersing steps.

The invention claimed is: 
     
       1. A stent comprising:
 a polymeric substrate, wherein the polymeric substrate comprises 30% (w/w) of alginate, 65% (w/w) of gelatine, and 5% (w/w) of contrast agent bismuth (III) carbonate; and 
 a polymeric biodegradable resin for coating the polymeric substrate, wherein the polymeric biodegradable resin comprises polycaprolactone resin. 
 
     
     
       2. The stent of  claim 1 , wherein the polymeric biodegradable resin further comprises at least one polymer biodegradable resin selected from the group consisting of polyglycolide, poly(lactic-co-glycolic acid with lactic acid), poly(glycolide-co-caprolactone) with ε-caprolactone, poly (glycolide-co-trimethylene carbonate) with trimethylene carbonate, and mixtures thereof. 
     
     
       3. The stent of  claim 1 , wherein the stent is a ureteral stent. 
     
     
       4. A stent comprising:
 a polymeric substrate wherein the polymeric substrate is formed by:
 (1) combining 30% (w/w) alginate, 65% (w/w) gelatine, and 5% (w/w) contrasting agent bismuth (Ill) carbonate, and 
 (2) adding a crosslinking agent; and 
 
 a polymeric biodegradable resin for coating the polymeric substrate formed in step (2), wherein the polymeric biodegradable resin comprises polycaprolactone resin. 
 
     
     
       5. The stent of  claim 4 , wherein the crosslinking agent is a chemical crosslinker comprising a functional group able to react with gelatine amines. 
     
     
       6. The stent of  claim 4 , wherein the crosslinking agent is an ionic crosslinking agent comprising monovalent or divalent ions in which the cation is selected from the group consisting of calcium, magnesium, barium, strontium, boron, beryllium, aluminium, iron, copper, cobalt, lead and silver, and the anion is selected from the group consisting of chloride, nitrate, phosphate, citrate, borate, succinate, maleate oxalate, and mixtures thereof. 
     
     
       7. The stent of  claim 4 , wherein the crosslinking agent is selected from a group consisting of: calcium chloride, genipin, glutaraldeyhyde, carbodiimides, and mixtures thereof. 
     
     
       8. The stent of  claim 4 , further comprising a therapeutic agent which is added to either the polymeric substrate or the polymeric biodegradable resin, wherein the therapeutic agent is selected from the group consisting of: an anti-inflammatory agent, an anti-microbial agent, an anti-cancer agent, an antiviral agent, and mixtures thereof. 
     
     
       9. The stent of  claim 8 , wherein the anti-inflammatory agent is selected from the group consisting of: prednisolone, methylprednisolone, fluorometholone, dexamethasone, betamethasone, hydrocortisone, medrysone, loteprednol, rimexolone, triamcinolone, diclofenac, ketorolac, flurbiprofen, indomethacin, suprofen, ibuprofen, ketorolac tromethamine, emedastine, levocabastine, azelastine, olopatadine, ketotifen, ketoprofen, cromolyn, iodoxamide, and mixtures thereof. 
     
     
       10. The stent of  claim 8 , wherein the anti-microbial agent is selected from the group consisting of: amoxicillin, dicloxacillin, augmentin, cephalosporins, gentamycin, tobramycin, neomycin, erythromycin, azithromycin, clarithromycin, ofloxacin, ciprofloxacin, norfloxacin, levofloxacin, and mixtures thereof. 
     
     
       11. The stent of  claim 8 , wherein the anti-cancer agent is selected from the group consisting of: methotrexate, vinblastine, doxorubicin, cisplatin, granulocyte colony-stimulating factor, gemcitabine, carboplatin, 5-fluorouracil, ifosfamide, pemetrexed, paclitaxel, epirubicin, mitomycin C, capecitabine,  Bacillus  Calmette-Guerin (BCG), and mixtures thereof. 
     
     
       12. The stent of  claim 8 , wherein the antiviral agent is selected from the group consisting of: acyclovir, valacyclovir, famciclovir, and mixtures thereof. 
     
     
       13. The stent of  claim 8 , wherein the therapeutic agent is added to the polymeric substrate. 
     
     
       14. The stent of  claim 8 , wherein the therapeutic agent is added to in the polymeric biodegradable resin.